Friday, 30 September 2022

Neurogenesis in species of Central American fish depends on presence of predation risk, research finds

SEPTEMBER 27, 2022, by Patrick Lejtenyi, Concordia University

Braeden Donaldson: "We wanted to see if there was an underlying neuroplastic response that correlates to certain behavioral changes. We found that there was.” 
Credit: Concordia University

Chemical alarm cues detected by a type of juvenile freshwater fish native to Central America result in noticeable increases in certain regions of their brains. That's according to new research by two Concordia scholars.

The paper was published in the Proceedings of the Zoological Society by Grant Brown, a professor of biology in the Faculty of Arts and Science, and his former student Braeden Donaldson, MSc 18. In it, they write that juvenile convict cichlids that are repeatedly exposed to high-risk alarm cues over a period of two weeks have brains that are on average 16 percent larger compared to a low-risk group. The growth, they note, is especially noticeable in specific regions of the brain: the high-risk group had on average 20 percent larger olfactory bulbs, 21 percent larger optic bulbs and 18 percent larger hypothalami.

The researchers also found that when the alarm cues were removed, the brains of the high-risk group reverted to the size comparable to those seen in the low-risk group after 11 days.

"We know, based on our previous research, that we will observe changes in the behavior of juvenile fish after 14 days of exposure to high-risk cues. The next step was to see what was happening in the brain," explains Donaldson, who is now pursuing his Ph.D. at the University of Victoria. "We wanted to see if there was an underlying neuroplastic response that correlates to these behavioral changes. We found that there was."

The high cost of neurogenesis

The researchers randomly assigned 86-day-old cichlids to one of two treatment groups. Each group consisted of five tanks containing shoals of 28 fish. One group was exposed to a solution made from processed skin from euthanized convict cichlids. This was deemed the high-risk group.

Like many other aquatic prey species, convict cichlids release a chemical cue when their skin or underlying viscera is damaged. This serves as a reliable and honest warning of the presence of a predation threat. The damaged skin was processed to create an alarm cue extract, which elicits antipredator behavior. The high-risk group was exposed to this extract three times a day for 14 days, simulating nearby predation events. The researchers introduced a similar amount—10 milliliters—of distilled water to the low-risk group, to control for the environmental disturbance. At the end of the 14-day period, half of the fish were removed from each of the 10 tanks for analysis.

The remaining fish were kept in their tanks and not exposed to any further disturbances for a further 11 days until they too were removed for analysis.

The results showed that the brains of the fish grow when they are repeatedly exposed to predation cues but revert when those cues are removed. The researchers cannot determine if the reversion is due to a slowing of brain growth or if it is the result of the rest of the fish's body catching up now that it has extra energy.

"We had predicted this reversal because neurogenesis—the production of neurons in the brain that cause it to grow—is energetically very expensive," Brown says. If an animal does not need to produce extra neurons as a survival mechanism, it will use that energy to grow in size, strength and sexual maturity. This, Brown asserts, suggests reversible neuroplasticity. The study adds to the work of Brendan Joyce, a Ph.D. student in Brown's lab, who has shown similar brain morphology changes in adult redbelly dace and juvenile Atlantic salmon.

"Twenty years ago, evolutionary biologists would look at behavioral decisions and say, 'The animal will do this or do that.' But it is more likely the case of, 'The animal can do this or do that,' depending on the environmental signals it is getting," Brown adds. "Variations in the environment, in food availability, mating, predation—all of these factor in and shape how an animal allocates its energy. And that is the idea of plasticity."



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Pupil dilation: A window to perception

SEPTEMBER 29, 2022, by Graciela Gutierrez, Baylor College of Medicine

Credit: Pixabay/CC0 Public Domain

The eyes are often referred to as the "windows to the soul." In fact, there is a grain of neurobiological truth to this. An international research team from the Universities of Göttingen and Tübingen, Germany, and Baylor College of Medicine in Houston, are now able to provide answers as to why pupil size is influenced by not only sensory stimuli like light, but also by our internal state such as fear, excitement or attention.

The findings, appearing in the current edition of Nature, help to explain whether these rapid, state-dependent changes in pupil size found not only in humans but also in other vertebrates, affect the way we perceive our surroundings.

Artificial intelligence for data analysis

Researchers started their work by investigating how state-dependent changes in pupil size affected the vision of mice.

"While the eyes convert light to neural activity, it is the brain which is crucial for the interpretation of visual scenes," said Dr. Katrin Franke, research group leader at the Institute for Ophthalmology Research at the University of Tübingen and first author of the study.

In their experiments, the researchers showed mice different colored images and recorded the activity of thousands of individual neurons within the visual cortex, a particularly relevant brain area for visual perception. Based on these recordings, they used deep neural networks to create a computer model as a digital twin of the cortex, simulating the responses of large numbers of neurons in the brain. They then used this computer model to identify the optimal visual light stimulus for each neuron, meaning each neuron's "favorite image."

Effects on visual perception

This model revealed something quite interesting: When the mice dilated their pupils due to an alert state of mind, the color sensitivity of the neurons changed from green to blue light within seconds, meaning neurons were more green sensitive in a quiet state and became more UV sensitive in an active state.

This was particularly true for neurons that sample stimuli from the upper hemisphere used to observe the sky. In subsequent experiments they were able to verify that this also happens in the real biological neurons.

With the help of eye drops that dilate the pupil, researchers were then able to simulate the higher sensitivity to blue light even for a quiet brain state.

"These results clearly demonstrate that pupil dilation due to an alert brain state can directly affect visual sensitivity and probably visual perception as well. The mechanism here is that a larger pupil lets more light into the eye, recruiting different types of photoreceptors in our retina and thus indirectly changing the color sensitivity in the visual cortex," Franke said.

But what are the benefits of this change in visual sensitivity? Konstantin Willeke, co-first author of the study and member of the research group led by adjunct professor of neuroscience at Baylor Dr. Fabian Sinz, said, "We were able to show that the higher neuronal sensitivity to blue light probably helps the mice to better recognize predators against a blue sky."

The computer model that the researchers created can also prove useful in many ways. Researchers are hoping others could use this model for further experiments to understand visual processing.

"Combining high throughput experimental data with AI modeling is opening a new era in neuroscience research. They enable us to extract accurate digital twins of real-world biological systems from data," said Sinz, who is currently professor at Göttingen University and one of the principal investigators of the study. "With these digital twins, we can perform an essentially unlimited number of experiments in a computer. In particular, we can use them to generate very specific hypotheses about the biological system which we can then verify in physiological experiments."

Dr. Andreas Tolias, also principal investigator on the study and professor and director of the Center for Neuroscience and Artificial Intelligence at Baylor, said, "The finding that brain state-related changes in pupil size affect visual sensitivity has implications for our understanding of vision well beyond predator detection in mice. Further research questions now arise as to how perception in numerous other animals is influenced by this effect. The pupils in our eyes could thus not only be a window into the soul, but also change the way we perceive the world from moment to moment depending on our inner state of mind."


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“ICELANDIC BLAST” TO GRIP EUROPE, AS IT STARES DOWN “COLD, DARK WINTER”; EARLY-SEASON SNOW CLIPS MINNESOTA, WARNINGS ISSUED NORTH OF THE BORDER; + GREENLAND’S RECORD START TO A SEASON

SEPTEMBER 29, 2022 CAP ALLON


“ICELANDIC BLAST” TO GRIP EUROPE…

An “Icelandic blast” is buffeting Western and Central Europe this week, bringing exceptionally frigid winds, snow and frost and threatening even colder conditions over the weekend and into next week.

UK meteorologists say winter is set to hit earlier than usual this year, thanks to 1) a deep low-pressure system spiraling towards Western Europe from Iceland, and 2) ex-Hurricane Fiona bolstering an anomalous high-pressure in the Atlantic.

“The cold weather will set in at the end of the weekend and looks like it isn’t going anywhere quickly,” said Jim Dale, meteorologist for the British Weather Services, who also predicts settling now for Scotland and frosts most-everywhere else.

“It is fair to say the seasons are about to make a dramatic transition to something much colder,” said Dale.

Lows of -3C (26.6F) –and beyond– are possible before the close of September, which in some locales would prove record-breaking — a dramatic turnaround that I’m sure our warm-mongering mainstream corporate media will dutifully relay to the public.

Today, for example, Sept 29, the coldest temperature ever recorded in the UK was the -4.4C (24.1F) set in West Linton in 1940.

The cold snap is also being driven by the remains of Hurricane Fiona, which threaten to “squeeze a lobe of cold air” over the UK. Rain will fall as snow falls over the higher elevations, and freezing lows will sweep much of Britain. This is according to the Met Office — “a cold plunge” is what they’re calling it, as “widely across the UK temperatures will be below average”.

And as revealed by the latest GFS run (shown below, which takes us through Friday), this “cold plunge” is already impacting far more than just Britain, with vast swathes of mainland Europe, including energy-stricken Germany, also shivering:

GFS 2m Temperature Anomalies (C) Sept 28 – Sept 30 [tropicaltidbits.com].

An early-season freeze the continent could have done without.

…AS IT STARES DOWN “COLD, DARK WINTER”

With its depleting energy reserves, driven alost entirely by poor foresight and planning, Europeans are inching towards a winter of hardships and difficult choices — and the colder the conditions, the harder the hardships.

Homes are almost assured of energy shortages, and for many, that will mean the heating, lights, fridges and ovens will be useless as plummeting temperatures grip the continent this winter.

Across Europe, statues and historic buildings are being left in dark in order to save energy, there are limitations on maximum heating temperatures, and businesses, such as bakeries, have been forced to shut up shop due to cripplingly-high prices, reported the AP, who add that European’s are also collecting firewood in record numbers in an attempt to keep to the fast-approaching cold season at bay.

FRANTIC ‘NET ZERO’ BACK-PEDALING

Prior to the war, EU nations met 40% of their energy needs using Russian gas. But with Moscow halting the supply, as they’re fully entitled to do by the way, natural gas prices have skyrocketed which is proving most-painful for the average citizen.

Nations that were once major advocates of reducing carbon emissions have now seen the folly of their ways and are firing back up coal and nuclear plants like they’re going out of fashion–which, of course, they had been for years prior thanks to the hijacking of reason and sense by those meaning-seeking Greens who, rather than loving the planet, as they endlessly profess, appear to hate humanity far more.

Modern human prosperity, health and well-being was built on the back of cheap and reliable energy, you rid our species of that and you resign billions –yes billions– of people to an existence of comparative ruin and suffering.

Despite its best efforts, the EU is failing to ramp up its natural gas production quickly enough because the infrastructure is simply no longer there. Many governments have even nationalized utility companies in order to save them from going bankrupt. And at this juncture, the depressing yet only viable option open is to try and save energy reserves for the coming winter — i.e. rationing.

These measures, although beneficial in the short term, will have dire consequences. Industrial shutdowns are tearing through the block like falling dominoes. Taking fertilizer production, as an example, with non-operation manufacturing plants there will be a chronic shortage of farming inputs come next spring — a drastic reduction in fertilizers means a drastic reduction in crop yields.

NORD STREAM “SABOTAGE”

Weeks after Moscow turned off the Nord Stream spigots, the pipelines have now been “sabotaged”, meaning Europe will have no choice but to survive winter without a single cubic foot of Russian gas.

The Nord Stream 1 pipeline, the energy lifeline of Europe, is made of two parallel branches. The pair of pipes run under the Baltic Sea from the Russian coast near St Petersburg to north-eastern Germany. Its twin, Nord Stream 2, was stopped as soon as Russia began its invasion of Ukraine. Despite being out of operation, the pipeline contained gas.


The European Union on Wednesday promised a “robust” response to any intentional disruption of its energy infrastructure after saying it suspected “sabotage” as being behind the gas leaks discovered this week on both branches of Nord Stream 1.

As gas spewed out under the Baltic Sea for a third day it remained far from clear who might be responsible. However, theories and finger pointing abound, with the U.S. and Russia themselves being top of the list of suspects.

“Any deliberate disruption of European energy infrastructure is utterly unacceptable and will be met with a robust and united response,” the EU foreign policy chief Josep Borrell said–which likely means precisely nothing.

Echoing the views of Germany, Denmark and Sweden, he said sabotage was likely, although the EU has not named a potential perpetrator or suggested a motive. While Washington, which has led efforts to punish Moscow over the war, believes it is too soon to conclude that there was sabotage, a senior U.S. military official said–wink-wink.

It is also possible that the taking out of Nord Stream is part of the oil price cap plan proposed by G7 nations –U.S., Japan, Germany, Britain, France, Italy, and Canada– along with the wider EU, which is a mechanism designed to hurt Russia.

Moscow however has made it clear that it won’t supply energy to any nation that signs up to it, likely deterring most other countries from supporting the plan.

Europe is currently brewing a major hurricane of its own with the entire globe susceptible to the storm surge.

EUROPE’S CRACKDOWN ON INFLATION IS ALREADY CRACKING

“Europe is very clearly heading into what could be a fairly deep recession,” said a former chief economist at the IMF.

The economic downturn has been aggravated by Central Bank’s efforts to tackle surging inflation by raising interest rates.

However, Wednesday saw two major global banks –one being the Bank Of England– pivoting with regards to their planned Quantitative Tightening (QT). The BoE has caved given the overwhelming economic threat and has returned to Quantitative Easing (QE) — i.e., it’s turned the money printers back on and has aimed them at squarely at an already inflated economy. This, although potentially saving the situation (the markets) in the short term, will only worsen inflation in the medium to long-term.

This act, particularly if it’s followed across the pond by the Fed has, at least to my mind, confirmed that a Great Depression-level collapse will hit once we catch up to this behemoth of a kicked can. But first, a potential euphoric FOMO parabola could sweep the stock markets, giving us one last hurrah before the mother of all crashes takes everyone out at the knees.

EARLY-SEASON SNOW CLIPS MINNESOTA…

Minnesota reported its first snowflakes of the season Tuesday morning.

According to the National Weather Service in Duluth, on and off flurries were noted along the Gunflint Trail in Cook County, with the likes of Ely also seeing some early-season flakes.


Worth noting, the average first measurable snowfall in Duluth is Oct 24 (with measurable snowfall defined as a tenth of an inch or more). The average in Rochester is Nov 4, with the earliest measurable on record their being Sept 26, 1942.

…WARNINGS ISSUED NORTH OF THE BORDER

“Winter is here,” reads the opening of a recent nnsl.com article.

Inches began settling Monday night, and blowing snow soon shuttered both the Dempster and the Inuvik Tuktoyaktuk Highways.

Warnings were issued by Environment Canada for the Northwest Territories, including Fort McPherson, Tsiigehtchic and Inuvik: “Visibility may be suddenly reduced at times in heavy snow,” read part of the ECCC release.

GREENLAND’S RECORD START TO A SEASON

While we’re up north, it should be noted that Greenland’s ice sheet has started the 2021-2022 season in impressive fashion.

The island has logged Surface Mass Balance (SMB) gains (blue line in the chart below) that have not only climbed above the 1981-2010 mean (grey line), but that have also nudged above the highest levels ever previously recorded (lighter grey ‘range’):

Danish Meteorological Institute (DMI)

Objectively looking at the data, Greenland hasn’t logged a ‘healthier’ start to a season in the 41 years of DMI record-keeping, and is continuing the ‘swing to gains’ which commenced back in 2013.


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Thursday, 29 September 2022

Cattle grazing with virtual fencing shows potential to create wildfire fuel breaks, study finds

SEPTEMBER 27, 2022, by Sean Nealon, Oregon State University

Cattle with collars for virtual fencing research by Oregon State University and the U.S. Department of Agriculture-Agricultural Research Service. 
Credit: Morgan Lawrence.

The use of virtual fencing to manage cattle grazing on sagebrush rangelands has the potential to create fuel breaks needed to help fight wildfires, a recent Oregon State University and U.S. Department of Agriculture-Agricultural Research Service study found.

Virtual fencing involves placing collars on livestock. The collars communicate with GPS and reception towers to form a virtual fence set by the rancher. Auditory stimuli emit from the collar when the livestock reach the limit of the virtual fence and they receive a benign shock if they pass the fence limit.

"We're seeing the challenge related to wildfires that land managers, particularly on public lands, are facing in the western U.S.," said David Bohnert, director of Oregon State's Eastern Oregon Agricultural Research Center in Burns. "They just don't have the tools to manage those public lands in a way that is timely, particularly related to wildfire. This new study should help begin to change that."

Wildfires on sagebrush landscapes, which cover much of the interior landscape of the western U.S., have increased dramatically in recent years, with more acres burning, the size of fires increasing and more federal dollars being spent to fight fires, USDA statistics show.

These changes are in part due to the expansion of nonnative annual grasses on the sagebrush landscape, the researchers note. The increased prevalence of these nonnative grasses, which dry out earlier in the growing season and grow faster than native perennial bunchgrass, leads to an increase in fuel for wildfires.

Most methods to reduce fuel for wildfires have focused on cutting or burning shrubs or trees. Recently there have been efforts to strategically place a network of fuel breaks across sagebrush landscapes to provide space where firefighters can safely seek to contain the spread of fires.

The new study from Oregon State and Agricultural Research Service scientists, published in Rangeland Ecology & Management, looked at whether cattle grazing and virtual fencing could be an effective tool to create those fuel breaks by eating the grass that fuels fires.

Virtual fencing has been around for decades, but in recent years, with advances in satellite, battery and GPS technology, it has gained more attention in the agricultural community, Bohnert said. It allows ranchers to control livestock distribution in rangeland landscapes without physical fences, which are costly to construct and maintain and also may be harmful to wildlife.


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Heavy floods ravage West Africa farmlands

SEPT. 27, 2022, by A. Abubakar with AFP bureaus in Libreville and Abidjan

Flooding has hit most states in Nigeria including northeast Adamawa State.

Nigeria rice farmer Adamu Garba squelched barefoot through his paddy fields, surveying damage from devastating floods that have destroyed farmland across the north of the country.

Parts of West and central Africa have been battered by floods ravaging farms like Garba's rice plots, wiping out crops and risking worsening food insecurity in a region already struggling with economic fallout from the Ukraine war.

Just in Nigeria, constant heavy rains caused the worst flooding in a decade, killing more than 300 people since the start of the rainy season and displacing at least 100,000, according to emergency officials.

"It is devastating but there is nothing we can do, we just have to be strong," Garba told AFP at his farm near the city of Kano, where he normally harvests 200 bags of rice.

"Now in the condition we find ourselves we are not sure we will harvest half a bag here."

Nigeria's National Emergency Management Agency (NEMA) spokesman Manzo Ezekiel said flooding has been unprecedented due to continuous rainfall with 29 of the country's 36 states affected.

"Thousands of farmlands have also been destroyed. The figures will rise further because we are still experiencing torrential rains and flooding," he said.

Flood waters were made worse partly by neighbouring Cameroon's release of excess waters from a dam and by Nigeria releasing waters to ease pressure on its Kainji and Jebba dams, Ezekiel said.

However, an official with Eneo, operator of Cameroon's Lagdo hydro-electricity plant, said excess waters released from the dam contributed only a small amount to flooding.

Parts of Nigeria, from northern farmlands to the coastal economic capital Lagos, are prone to flooding in the rainy season, though NEMA says this year is the worst since 2012, when 363 people died and more than 2.1 million were displaced.

Flood waters have hit across West Africa.

Climate change

The Niger river—West Africa's main river—flows through northern Niger past Benin's northern border into Nigeria before reaching in the Gulf of Guinea on the Atlantic through southern Nigeria's Niger Delta.

Heavy rains falling in Niger since June and the severe floods have claimed 159 lives and affected more than 225,000 people, making this rainy season one of the deadliest in history, emergency officials said earlier this month.

"According to our studies, we can link these rains to climate change in general," said Katiellou Gaptia Lawan, Director General of National Meteorology of Niger.

"The rains are becoming more and more intense and the extreme precipitation is increasing."

Rains in Niger this year have also totally destroyed or damaged more than 25,900 homes, and impacted farmland and cattle, authorities said.

The June to September rainy season regularly kills people in Niger, including in the northern desert areas, but the toll is particularly heavy this year.

In 2021, 70 people died and 200,000 were affected.

In Chad, the UN said more than 622,500 people had been affected "at different levels" by flooding in more than half of the country, including the capital N'Djamena, with most impacted areas bordering the north of Cameroon.

According to the United Nations, in 2021, 5.5 million Chadians, more than a third of the population of the landlocked country were already in need of emergency humanitarian aid, even before the floods.

In northern Nigeria, Kabiru Alassan, a 19-year old farmer, said flood waters washed sand from the roads and covered his rice fields. But he was trying to salvage what he could.

"This is the little we have left by Allah's grace which we are going to harvest," he said.

"The rains have never been this destructive. We pray never to experience such a nightmare."



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Scientists propose that obesity is a neurodevelopmental disorder

SEPTEMBER 28, 2022 by Baylor College of Medicine

Credit: Pixabay/CC0 Public Domain

Obesity has increased rapidly in recent decades to affect more than 2 billion people, making it one of the largest contributors to poor health worldwide. Despite decades of research on diet and exercise treatments, many people continue to struggle to lose weight. Researchers at Baylor College of Medicine and collaborating institutions now think they know why, and say we must shift the focus from obesity treatment to prevention.

The team reports in the journal Science Advances that molecular mechanisms of brain development during early life are likely a major determinant of obesity risk. Previous large studies in humans have hinted that genes that are most strongly associated with obesity are expressed in the developing brain. This current study in mice focused on epigenetic development. Epigenetics is a system of molecular bookmarking that determines which genes will, or will not, be used in different cell types.

"Decades of research in humans and animal models have shown that environmental influences during critical periods of development have a major long-term impact on health and disease," said corresponding author Dr. Robert Waterland, professor of pediatrics-nutrition and a member of the USDA Children's Nutrition Research Center at Baylor. "Body weight regulation is very sensitive to such 'developmental programming,' but exactly how this works remains unknown."

"In this study we focused on a brain region called the arcuate nucleus of the hypothalamus, which is a master regulator of food intake, physical activity and metabolism," said first author Dr. Harry MacKay, who was a postdoctoral associate in the Waterland lab while working on the project. "We discovered that the arcuate nucleus undergoes extensive epigenetic maturation during early postnatal life. This period is also exquisitely sensitive to developmental programming of body weight regulation, suggesting that these effects could be a consequence of dysregulated epigenetic maturation."

The team conducted genome-wide analyses of both DNA methylation—an important epigenetic tag—and gene expression, both before and after closure of the postnatal critical window for developmental programming of body weight. "One of our study's biggest strengths is that we studied the two major classes of brain cells, neurons and glia," MacKays said. "It turns out that epigenetic maturation is very different between these two cell types."

"Our study is the first to compare this epigenetic development in males and females," Waterland said. "We were surprised to find extensive sex differences. In fact, in terms of these postnatal epigenetic changes, males and females are more different than they are similar. And, many of the changes occurred earlier in females than in males, indicating that females are precocious in this regard."

The human connection

The biggest surprise came when the investigators compared their epigenetic data in mice to human data from large genome-wide association studies that screen for genetic variants associated with obesity. The genomic regions targeted for epigenetic maturation in the mouse arcuate nucleus overlapped strongly with human genomic regions associated with body mass index, an index of obesity.

"These associations suggest that obesity risk in humans is determined in part by epigenetic development in the arcuate nucleus," MacKay said. "Our results provide new evidence that developmental epigenetics is likely involved in both early environmental and genetic influences on obesity risk. Accordingly, prevention efforts targeting these developmental processes could be the key to stopping the worldwide obesity epidemic."

Other contributors to this work include Chathura J. Gunasekara, Kit-Yi Yam, Dollada Srisai, Hari Krishna Yalamanchili, Yumei Li, Rui Chen and Cristian Coarfa. The authors are affiliated with one or more of the following institutions: Baylor College of Medicine, Vanderbilt University, Jan and Dan Duncan Neurological Research Institute atTexas Children's Hospital and Baylor's Dan L Duncan Comprehensive Cancer Center.


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Dogs can smell when we're stressed, study suggests

SEPTEMBER 28, 2022, by Public Library of Science

A study dog sniffing a person's breath and sweat sample. Credit: Kerry Campbell, CC-BY 4.0 (creativecommons.org/licenses/by/4.0/)

The physiological processes associated with an acute psychological stress response produce changes in human breath and sweat that dogs can detect with an accuracy of 93.75%, according to a new study published this week in the open-access journal PLOS ONE by Clara Wilson of Queen's University Belfast, U.K., and colleagues.

Odors emitted by the body constitute chemical signals that have evolved for communication, primarily within species. Given dogs' remarkable sense of smell, their close domestication history with humans, and their use to support human psychological conditions such as anxiety, panic attacks and post-traumatic stress disorder (PTSD), researchers wondered whether dogs could be sensing chemical signals to respond to their owners' psychological states.

In the new study, the researchers collected samples of breath and sweat from non-smokers who had not recently eaten or drank. Samples were collected both before and after a fast-paced arithmetic task, along with self-reported stress levels and objective physiological measures: heart rate (HR) and blood pressure (BP).

Samples from 36 participants who reported an increase in stress because of the task, and experienced an increase in HR and BP during the task, were shown to trained dogs within three hours of being collected. Four dogs of different breeds and breed-mixes had been trained, using a clicker as well as kibble, to match odors in a discrimination task. At testing, dogs were asked to find the participant's stress sample (taken at the end of the task) while the same person's relaxed sample (taken only minutes before, prior to the task starting) was also in the sample line-up.

Overall, dogs could detect and perform their alert behavior on the sample taken during stress in 675 out of 720 trials, or 93.75% of the time, much greater than expected by chance (p<0.001). The first time they were exposed to a participant's stressed and relaxed samples, the dogs correctly alerted to the stress sample 94.44% of the time. Individual dogs ranged in performance from 90% to 96.88% accuracy.

The authors conclude that dogs can detect an odor associated with the change in Volatile Organic Compounds produced by humans in response to stress, a finding that tells us more about the human-dog relationship and could have applications to the training of anxiety and PTSD service dogs that are currently trained to respond predominantly to visual cues.

The authors add: "This study demonstrates that dogs can discriminate between the breath and sweat taken from humans before and after a stress-inducing task. This finding tells us that an acute, negative, psychological stress response alters the odor profile of our breath/sweat, and that dogs are able to detect this change in odor."


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Medical Science News: How can we stop the opioid crisis? It involves medical cannabis - study

How can we stop the opioid crisis? It involves medical cannabis - study


90.6% of study participants found medical cannabis to be very or extremely helpful in treating their medical condition.


Wednesday, 28 September 2022

Researchers reconstruct the genome of the common ancestor of all mammals

SEPTEMBER 27, 2022, by Andy Fell, UC Davis

An international team has reconstructed the genome organization of the earliest common ancestor of all mammals. 
The reconstructed ancestral genome could help in understanding the evolution of mammals and in conservation of modern animals. 
The earliest mammal ancestor likely looked like this fossil animal, Morganucodon, which lived about 200 million years ago. 
Credit: Wikipedia by user Funkmonk, Creative Commons Attribution-Share Alike 3.0 Unported license

Every modern mammal, from a platypus to a blue whale, is descended from a common ancestor that lived about 180 million years ago. We don't know a great deal about this animal, but the organization of its genome has now been computationally reconstructed by an international team of researchers. The work is published Sept. 30 in Proceedings of the National Academy of Sciences.

"Our results have important implications for understanding the evolution of mammals and for conservation efforts," said Harris Lewin, distinguished professor of evolution and ecology at the University of California, Davis, and senior author on the paper.

The researchers drew on high-quality genome sequences from 32 living species representing 23 of the 26 known orders of mammals. They included humans and chimps, wombats and rabbits, manatees, domestic cattle, rhinos, bats and pangolins. The analysis also included the chicken and Chinese alligator genomes as comparison groups. Some of these genomes are being produced as part of the Earth BioGenome Project and other large-scale biodiversity genome sequencing efforts. Lewin chairs the Working Group for the Earth BioGenome Project.

The reconstruction shows that the mammal ancestor had 19 autosomal chromosomes, which control the inheritance of an organism's characteristics outside of those controlled by sex-linked chromosomes (these are paired in most cells, making 38 in total), plus two sex chromosomes, said Joana Damas, first author on the study and a postdoctoral researcher at the UC Davis Genome Center. The team identified 1,215 blocks of genes that consistently occur on the same chromosome in the same order across all 32 genomes. These building blocks of all mammal genomes contain genes that are critical to developing a normal embryo, Damas said.

Chromosomes stable over 300 million years

The researchers found nine whole chromosomes or chromosome fragments in the mammal ancestor, whose order of genes is the same in modern birds' chromosomes.

"This remarkable finding shows the evolutionary stability of the order and orientation of genes on chromosomes over an extended evolutionary timeframe of more than 320 million years," Lewin said.

In contrast, regions between these conserved blocks contained more repetitive sequences and were more prone to breakages, rearrangements and sequence duplications, which are major drivers of genome evolution.

"Ancestral genome reconstructions are critical to interpreting where and why selective pressures vary across genomes. This study establishes a clear relationship between chromatin architecture, gene regulation and linkage conservation," said Professor William Murphy, Texas A&M University, who was not an author on the paper. "This provides the foundation for assessing the role of natural selection in chromosome evolution across the mammalian tree of life."

The researchers were able to follow the ancestral chromosomes forward in time from the common ancestor. They found that the rate of chromosome rearrangement differed between mammal lineages. For example, in the ruminant lineage (leading to modern cattle, sheep and deer) there was an acceleration in rearrangement 66 million years ago, when an asteroid impact killed off the dinosaurs and led to the rise of mammals.

The results will help understanding the genetics behind adaptations that have allowed mammals to flourish on a changing planet over the last 180 million years, the authors said.


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A “Previously Unrecognized Link” – Land Plants Caused a Sudden Shift in Earth’s Composition

UNIVERSITY OF SOUTHAMPTON SEPTEMBER 27, 2022


According to the researchers, the proliferation of plants completely altered the biosphere of Earth.

A new study reveals that land plants changed Earth’s composition.

According to research from the University of Southampton, the Earth’s continents’ composition suddenly shifted as a result of the evolution of land plants.

In collaboration with colleagues from Queen’s University Canada, the University of Cambridge, the University of Aberdeen, and the China University of Geosciences, Wuhan, the Southampton researchers—led by Dr. Tom Gernon—studied the effects of land plant evolution on Earth’s chemical composition over the course of the previous 700 million years.

The researchers’ findings were recently published in Nature Geoscience.


Ferns were some of the first land plants to colonize the continents, with some analysis indicating that they evolved about 430 million years ago. The scientists report a step change in the composition of the continental crust at precisely this time, which they relate to fundamental changes in river systems tied to the evolution of land plants.
 Credit: Dr. Tom Gernon / University of Southampton




Around 430 million years ago, during the Silurian Period, when North America and Europe were connected to form the continent known as Pangaea, the evolution of land plants took place.

Plants drastically modified Earth’s biosphere (those regions of the planet’s surface where life flourishes), laying the stage for the emergence of dinosaurs around 200 million years later.

“Plants caused fundamental changes to river systems, bringing about more meandering rivers and muddy floodplains, as well as thicker soils,” says Dr. Christopher Spencer, Assistant Professor at Queen’s University in Kingston, Ontario, lead author of the study. “This shift was tied to the development of plant rooting systems that helped produce colossal amounts of mud (by breaking down rocks) and stabilized river channels, which locked up this mud for long periods.”

The scientists recognized that plate tectonics connects the Earth’s surface and deep core: rivers wash mud into the oceans, and this mud is subsequently carried into the Earth’s molten interior (or mantle) at subduction zones, where it melts to produce new rocks.

The team recognized changes in the composition of rocks formed by the melting of Earth’s interior at subduction zones where major tectonic plates collide. The present-day subduction volcano shown here is Avachinsky, Kamchatka. 
Credit: Dr. Tom Gernon / University of Southampton

“When these rocks crystallize, they trap in vestiges of their past history,” says Dr. Tom Gernon, Associate Professor of Earth Science at the University of Southampton and co-author of the study. “So, we hypothesized that the evolution of plants should dramatically slow down the delivery of mud to the oceans and that this feature should be preserved in the rock record – it’s that simple.”

To test this idea, the team studied a database of over five thousand zircon crystals formed in magmas at subduction zones – essentially ‘time capsules’ that preserve vital information on the chemical conditions that prevailed on Earth when they crystallized.


The present-day subduction volcano shown here is the Island of Montserrat, West Indies. 
Credit: Dr. Tom Gernon / University of Southampton




The team uncovered compelling evidence for a dramatic shift in the composition of rocks making up Earth’s continents, which coincides almost precisely with the onset of land plants.

Notably, the scientists also found that the chemical characteristics of zircon crystals generated at this time indicate a significant slowing down of sediment transfer to the oceans, just as they had hypothesized.

The researchers show that vegetation changed not only the surface of the Earth but also the dynamics of melting in Earth’s mantle.

“It is amazing to think that the greening of the continents was felt in the deep Earth,” concludes Dr. Spencer.

“Hopefully this previously unrecognized link between the Earth’s interior and surface environment stimulates further study.”


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OF 68 GLOBAL WARMING MODELS THE OBSERVED TEMPERATURE IS RUNNING *BELOW* 67 OF THEM

SEPTEMBER 27, 2022 CAP ALLON


The claim by the Biden Administration that cLiMaTe ChAnGe has placed us in a moment of “profound crisis” is based on computer model simulations that have manufactured warming rates of at least double those observed in the last 40+ years.

This is according to Dr. Roy Spencer, climatologist and former NASA scientist, who also points out that just about every climate claim made by politicians and activist-scientists alike has been either an exaggeration or an outright lie.

Real-world observations are in stark disagreement with the “official” climate models being promoted for the purposes of implementing expensive, economically-damaging, and poverty-worsening energy policies.

Let’s take Global Ocean Temperatures as one example–with Sea Surface Temperatures (SSTs) providing our best gauge of how fast this supposed extra energy is accumulating in the climate system.

The 42 years of observations since 1979 (black line on the chart below) shows that warming is occurring far more slowly than the models said it would. The ERSSTv5, one of the top-cited datasets, reveals that Earth’s oceans have warmed at ≈50% the rate official climate projections foretold.

In fact, there has been barely any warming.

68x CMIP6 climate model simulations of global average sea surface temperature (relative to the 5 year average, 1979-1983), compared to observations from the ERSSTv5 dataset (aka the reality).

To put it even more clearly –so alarmists can take it in– of the 68 model simulations that have been generated over the years, 67 are ABOVE the current observations, with the majority significantly above, by over a full 1 deg. C in some cases.

The global warming hypothesis has failed, that is clear for all to see. It isn’t science that’s propping the charade up; rather, this is a political and ideological movement, one that after decades of relentless propaganda now has a large percentage of western populations fooled and radically onboard.

Helpfully, Dr. Spencer has provided us with another graph that might drag a few ‘brainwashed pawns’ back from that precipice.

In terms of the linear temperature trends since 1979, the image below shows that the two top-cited ocean temperature datasets –i.e. those based on observations– have trends at the bottom range of climate model simulations:

Linear temperature trends, 1979-2020, for the various model and observational datasets, plus the HadSST3 observational record.

This should be a ‘head in hands’ moment for the climate modelers.

But humility has never proved their strong point.

DEEP OCEAN WARMING COULD BE NATURAL

Furthermore, a related issue here is how much the deep oceans are warming.

The inarguable energy imbalance associated with deep-ocean warming in recent decades is only about 1 part (less than 1 Watt per sq. m) in 300 of the natural energy flows in the climate system.

This is a minuscule energy imbalance.

We know precisely NONE of the natural energy flows to that level of accuracy, adds Dr. Spencer, meaning global warming could be mostly/entirely natural and we wouldn’t even know it:

“[There is a] level of faith involved in the adjustments made to climate models, which necessarily produce warming due to increasing CO2 because those models simply assume that there is no other source of warming. Seldom is the public ever informed of these glaring discrepancies between basic science and what politicians and pop-scientists tell us.”

Dr. Roy Spencer concludes: “There is no Climate Emergency.”

How The Greenland Ice Sheet ‘REALLY’ Fared This Year


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Medical Science News: Could ancient genes be the key to solving modern-day sicknesses? - study

Could ancient genes be the key to solving modern-day sicknesses? - study


The genes, called 'retrotransposon Gag-like' 5 and 6 (Rtl5 and Rtl6), are found in nearly all mammals.